Grain legumes, including cowpea, are the cheapest sources of minerals and protein to enhance human nutrition. Cultivar development and deployment of cowpea with increased grain mineral content and protein composition rely on selection of genetically unique and complementary breeding lines. The objective of this study was to assess the grain minerals and protein composition of diverse cowpea collections of eastern, southern and western Africa to select promising parents to develop a breeding population. Twenty-two genetically diverse cowpea genotypes were field evaluated using a randomised complete block design with three replications in two locations in South Africa. The dried grain mineral contents were determined using an Atomic Absorption Spectrophotometre, while the protein content was determined by the combustion method. Analyses of variance showed significant (P < 0.05) effects of genotypes, locations and their interactions. The test genotypes showed considerable variation for the following nine mineral contents: calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), and zinc (Zn) varying from 0.07 to 0.12 mg kg⁻¹; 4.46 to 7.81 mg kg⁻¹; 0.06 to 0.11 g; 11.82 to 14.45 g; 1.86 to 2.27 g; 9.24 to 13.30 mg kg⁻¹; 0.26 to 0.80 g; 4.63 to 5.92 g and 0.03.00 to 0.05 g, respectively. Further, the total protein content varied from 23.16 to 28.13%. Significant correlations were detected among some mineral elements and total protein content, suggesting the possibility of simultaneous selection for these traits. The principal component analysis (PCA) identified four principal components (PCs) contributing to 70.93% of the total explained variation amongst genotypes. Overall the following genotypes with desirable grain mineral and protein attributes were selected: IT90K-59 (Ca), 98K-5301 (Ca and protein), ITOOK-1060 (Cu), ITOOK-1217 and IT845-2246 (Fe), Bensogla (K, Na, and P), TVU11424 and ITOOK-1217 (Mg), CH14 (Mn and Na), TVU12637 (Mn) and Glenda and Vuli (Zn). The selected cowpea genotypes are useful genetic resources for population and cultivar development for grain nutrients composition.

Maize (Zea mays L.) is the main staple cereal food crop cultivated in southern Africa. Interactions between grain yield and biochemical traits can be useful to plant breeders in making informed decisions on the traits to be considered in breeding programs for high grain yield and enhanced quality. The objectives of this study were to estimate the heritability of grain yield and its related traits, as well as quality traits, and determine the association between quality protein maize (QPM) with non-QPM crosses. Grain yield, and agronomic and quality trait data were obtained from 13 field trials in two countries, for two consecutive seasons. Significant genotypic and phenotypic correlations were recorded for grain yield with protein content (r_G = 0.38; r_P = 0.25), and tryptophan with oil content (r_G = 0.58; r_P = 0.25), and negative r_G and r_P correlations were found for protein with tryptophan content and grain yield with tryptophan content. Path analysis identified ear aspect, ears per plant, and starch as the major traits contributing to grain yield. It is recommended that ear aspect should be considered a key secondary trait in breeding for QPM hybrids. The negative association between grain yield and tryptophan, and between protein and tryptophan, will make it difficult to develop hybrids with high grain yield and high tryptophan content. Hence, it is recommended that gene pyramiding should be considered for these traits.

Drought stress triggers remarkable physiological changes and growth impediments, which significantly diminish plant biomass and crop yield. However, certain plant species show notable resilience, maintaining nearly normal yields under severe water deficits. For example, sorghum is a naturally drought-tolerant crop, which is ideal for studying plant adaptive responses to drought. Here we used sorbitol treatments to simulate drought-induced osmotic stress in sorghum cell suspension cultures and analysed fractions enriched for extracellular matrix proteins using isobaric tags for relative and absolute quantification technology. Sorbitol induced an overall increase in protein secretion, with putative redox proteins, proteases, and glycosyl hydrolases featuring prominently among the responsive proteins. Gene expression analysis of selected candidates revealed regulation at the transcriptional level. There was a notable differential gene expression between drought-tolerant and drought-sensitive sorghum varieties for some of the candidates. This study shows that protein secretion is a major component of the sorghum response to osmotic stress. Additionally, our data provide candidate genes, which may have putative functions in sorghum drought tolerance, and offer a pool of genes that could be developed as potential biomarkers for rapid identification of drought tolerant lines in plant breeding programs.

Sorghum is a drought tolerant cereal and staple food which is a dietary source of protein and more than 20 minerals. The concentration of the mineral elements and protein content in sorghum varies due to genotypic and environmental influences and genotype by environment interactions. The objective of this study was to determine the contents of eight mineral elements (Ca, Fe, K, Mn, Na, P, Zn and Mg) and protein in sorghum genotypes. The analysis of variance showed significant differences in mineral and protein contents. There was a significant relationship between Zn and Fe and between protein and P and Zn. The principal component (PC) analysis showed that Fe, Mn, P, Zn and protein contributed largely to clustering of the genotypes in PC1; Ca, P and Mg to PC2 and Ca, K and Na to PC3. The presence of a considerable amount of compositional variability of mineral and protein contents among tested genotypes suggests that they can be a valuable source of genes for nutritional quality improvement of sorghum.

Sorghum (Sorghum bicolor (L.) Moench) is a staple food grain in many semi-arid and tropical areas of the world, notably in sub-Saharan Africa because of its adaptation to harsh environments. Among important biochemical components for sorghum for processors are the levels of starch (amylose and amylopectin) and total sugar contents. The aim of this study was to determine the genetic variation for total starch in the seed, its components and total sugar in the stalks of the sorghum accessions from Ethiopia and South Africa. Samples of 22 sorghum accessions were evaluated. Significant variations were observed in total starch (31.01 to 64.88 %), amylose (14.05 to 18.91 %), the amylose/amylopectin ratio (0.31 to 0.73) and total stalk sugar content (9.36 to 16.84 %). Multivariate analysis showed a wide genetic variation within and among germplasm accessions which could be used in the selection of parental lines for the improvement of traits of interest through breeding. The variation found among the sorghum accessions shows that an improved total starch and starch components and stalk sugar contents can be achieved through crossing these selected genotypes

Malnutrition, as a result of deficiency in essential nutrients in cereal food products and consumption of a poorly balanced diet, is a major challenge facing millions of people in developing countries. However, developing maize inbred lines that are high yielding with enhanced nutritional traits for hybrid development remains a challenge. This study evaluated 40 inbred lines: 26 quality protein maize (QPM) lines, nine non-QPM lines, and five checks (three QPM lines and two non-QPM lines) in four optimum environments in Zimbabwe and South Africa. The objective of the study was to identify good-quality QPM inbred lines for future hybrid breeding efforts in order to increase the nutritional value of maize. The QPM lines had a lower protein content (7% lower) than that of the non-QPM lines but had 1.9 times more tryptophan and double the quality index. The lysine- and tryptophan-poor α-zein protein fraction was 41% lower in QPM than in non-QPM, with a subsequent increase in γ-zein. There was significant variation within the QPM inbred lines for all measured quality characteristics, indicating that the best lines can be selected from this material without a yield penalty. QPM lines that had both high protein and tryptophan levels, which can be used as parents for highly nutritious hybrids, were identified.